The pharmacological mechanisms by which phencyclidine (PCP) affects behavior and the neurochemical consequences of PCP abuse are unknown. This research is designed to determine the distribution of PCP in brain and to relate this distribution to the effects of acute and chronic administration of PCP on neurotransmitter receptor mechanisms and functional metabolic activity within the brain. The distribution of (3H)-PCP within the brain will be studied by light microscope autoradiographic techniques. The effects of acute and chronic administration of PCP on neutrotransmitter receptor mechanisms will be studied by using receptor binding techniques and by measuring the effects of PCP on the cAMP generating systems in brain areas. In addition, the characteristics of (3H)-PCP binding to brain membrane fractions will be measured. The effects of acute and chronic administration of PCP on functional metabolic activity within discrete brain areas will be determined by measuring the rate of (14C)-2-deoxyglucose uptake. The integration of the results of these studies should provide a picture of the sites, synaptic mechanisms of action and metabolic consequences of acute and chronic PCP administration.